A kitchen machine of the kind mentioned in the opening paragraph is known from German Patent 26 00 399. The housing of the known kitchen machine comprises a base and a column positioned on the base. The bowl can be placed on the base next to the column and has its rotation bearings on the base. A transverse arm is provided on the column, extending to above the bowl with pivoting possibility relative to the column. The transmission arranged in the transverse arm can be driven by the electric motor of a handmixer which is a part of to the kitchen machine and which can be placed on the transverse arm, in which position an output shaft of the handmixer is coupled to the transmission. The drive wheel is a pinion which is in engagement with a toothed rim provided along an outer circumference of the bowl and which is coupled to the transmission. During operation, the tool rotates at a comparatively high speed relative to the bowl, while the bowl rotates at a comparatively low speed relative to the base.
A disadvantage of the known kitchen machine is that the electric motor can be switched on while the rotatable bowl is absent or is incorrectly placed on the base. If the bowl has not been placed on the base, a user of the kitchen machine may readily injure himself or herself with the rotating tool. If the bowl has been incorrectly placed on the base the pinion will not engage the toothed rim of the bowl, so that the kitchen machine will function incorrectly.